“We have started on US commercial crew transportation,” Bill Gerstenmaier, NASA Associate Administrator for Human Exploration and Operations at NASA HQ, Washington D.C., told Sen. “NASA awarded the two commercial crew program [CCP] contracts to Boeing and SpaceX and there is a lot of work ongoing.”

The loss last week of Russia’s Progress resupply freighter when it unexpectedly spun out-of-control soon after launching atop a Soyuz-2-1a carrier rocket from the Baikonur Cosmodrome in Kazakhstan highlighted the space station's ever present dependency on a regular regimen of robust booster rockets and transport vessels to carry both human crews and essential supplies to orbit.

Indeed the twin failures of the Russian Progress M-27M freighter on May 8, and the Oct. 28, 2014 catastrophic explosion of the Orbital ATK Antares rocket carrying the Cygnus cargo ship, also reinforced the wisdom of having multiple backups for crew and cargo in case something goes awry, since rocket science is inherently risky and unforgiving of errors and shortcuts.

A further reminder that spaceflight is never routine came on Saturday (May 16) with the launch failure of a Russian Proton rocket that resulted in complete destruction of its payload, a Mexican telecommunications satellite.

We are now hopefully past the midway point between the forced shutdown of NASA’s Space Shuttle orbiters in July 2011 and the inaugural test flights of the SpaceX Crew Dragon and Boeing CST-100 astronaut transporters as soon as 2017, if all goes according to plan and the U.S. Congress provides the funding to keep the launch schedule on track.

Significant year over year cuts to NASA’s requested commercial crew funding have already forced a two year postponement from 2015 to 2017 in the resumption of human spaceflight launches from U.S. soil aboard US rockets. After the shuttle’s grounding following the STS-135 grand finale mission in July 2011, each and every astronaut and cosmonaut has been 100 per cent dependent on Russia’s three person Soyuz capsule. That sole dependence should come to an end as soon as 2017.

When the private space taxi era starts it will herald a return to the pattern of previous decades of flying mixed multinational crews of spaceflyers to the ISS from both US and Russian rocket bases.

“Commercial crew will not end our relationships with the Russians,” Gerstenmaier stated. “It will just end our sole reliance on the Russians. We will still fly on each other’s spacecraft.

"Russians will fly on our commercial crew vehicles. And our NASA astronauts will still fly on Soyuz. We will truly match each other up.”

There are also long term strategic advantages to this, in addition to maintaining relationships.

“That way if someone has to stand down and can’t fly for a period of time, we can still fly on the other persons spacecraft.”

The Russian-American partnership was especially critical following the Space Shuttle Columbia disaster. “When we had the Columbia tragedy, if it wasn’t for the Soyuz we would have had to decrew the space station. So the Russians essentially helped us during that period.

“So we want to have that same capability here with commercial crew transportation, so we are not solely reliable on the Soyuz.”

“The Russians would also like to have some backup capability, in case something happens.”

In September 2014, NASA Administrator Charles Bolden announced that Boeing and SpaceX had won the high stakes commercial crew program (CCP) competition and gave them the go ahead to finish development and begin construction of the world’s first ever private space taxis designed to ferry humans crew to the space station.

Since then NASA and contractor officials and astronauts have all been working diligently to restore America’s indigenous human spaceflight capability.

“Lots of [CCP] activities have stated happening,” Gerstenmaier elaborated. “SpaceX did its first abort test in May in Florida. It’s done off the pad with the Dragon capsule. Boeing recently did a water landing test at NASA Langley. Boeing is also starting to put systems together to build the CST-100 down at the Cape [in the former shuttle OPF].”

“Boeing is making pad changes down at the Cape at Pad 41.” The CST-100 will launch from Cape Canaveral, Florida on a man-rated United Launch Alliance Atlas V booster.

Construction of the crew access tower for the CST-100. Image credit: NASA

“SpaceX is making pad changes to Pad 39A. NASA turned that pad over to SpaceX. It used to be used for space shuttle launches, along with Pad 39B. Pad 39A is being modified to make it a launch pad for humans again [using the SpaceX Falcon 9 rocket].

“So we are also starting to get our crews ready to fly in the CST-100 and the Dragon. There’s really a lot of tremendous work ongoing.”

“So eventually, we will end our sole dependence on the Russians for flying crews to orbit.”

The Russian Soyuz Crew capsule and Progress resupply vessel, American SpaceX Cargo Dragon and Orbital ATK Cygnus, as well as the Japanese HTV vessels serve as the current lifeline for maintaining continuous, safe and productive habitation and research aboard the million pound (half million kg) orbiting outpost soaring some 250 miles (400 km) above our home planet.